Solenoid.



R. 0. DA COSTA. SOLENOID.

APPLICATION FILED APR- 3, 1912.

1,142,027. I Patented June 8, 1915.

a (5/ I Z y fa QWQJL Max/ J J I I I Maw/ 2% UNITED STATES PATENT orrica ROBERT 0. DA COSTA, TRENTON, NEW JERSEY, ASSIGNOR T0 JQHN'A. BOEBLI'NG SOHS COMPANY, A CORPORATION OF NEW (HWY.

To all whom it may concern Be it known that 1, ROBERT C. DA Come, a citizen of the United States, residing at Trenton, county of Mercer, and State of New Jersey, have invented certain new and useful Improvements in Solenoids, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to the construction a of solenoids including magnet coils and the like and has to do particularly with the construction of an electrical coil having an improved inner terminal conductor.

Commonly it is the practice to use -the wire of the coil itself as the inner terminal, a few inches of it at the beginning of the winding being allowed to extend beyond the core so as to provide the necessary connection. A coil constructed in this manner has the disadvantage of being rendered useless should the inner terminal be broken off, a not uncommon occurrence. To remedy this defect two or more wires are sometimes twisted together to form the inner terminal, making it less liable to breakage; but in many cases these wires'also are broken, with the same result.

One object of the present invention is to provide a terminal which cannot be broken off in this manner.

Another object is to provide a terminal to which connection may be made with equal facility at either end of the coil, this being of advantage in many cases.

Still another object is to provide a coil in the form of a complete electrical solenoid that is portable, not easily damaged, and which may be used for a great variety of purposes without requiring any special adaptation therefor.

Referring to the drawings, Figure 1 is a view in perspective showing the general construction of the coil and its terminal, and Fig. 2 is a cross section of the same.

The foundation of the coil is a suitable spool or bobbin which carries a longitudinal conductor and upon which the coil is-wound. In the present instance, this spool or bobbin is shown as a tube composed of twolayers of paper 1 and 2. Between these layers of paper and insulated thereby is a longitudinal conductor a, preferably in the form of a flat copper strip. The ends of the conductor a project slightly beyond the tube so that a Specification of Letters Patent.

Patented June 8, 1915.

Application am A ril 3, 1912. serial 1h. esaaoa.

conducting wireb may be soldered to either =or to both ends, and if broken ofi, may

readily berenewed. In'making the coil, the outer layer of paper 2 is removed at any suitable point above the conductor a, as at 3, so that the inner end of the coil wire 0 may be soldered thereto or otherwise held in electrical connection therewith. The inner end of the wire 0 is fully protected from any possible breakage, and the other termiother conducting and insulating materials may be used in their places respectively without any departure from the invention. Likewise the particular form these parts are made to assume may be greatly varied and the resulting structure still remain within the range of the invention.

What is claimed is:

1. The combination, with a spool formed of insulating material having a conductor buried in the material and thereby insulated, said conductor having an exposed bared end, said spool being provided at its periphery intermediate its ends with a pocket or recess exposing a portion of said conductor, of an electric coil of insulated wire wound upon said spool and having its inner end bared and in contact with the conductor in said pocket or recess.

2. The combination, with a spool formed of insulating material having a conductor buried in the material and thereby insulated, said conductor having exposed portions at each end of the spool, said spool being provided at its periphery intermediate its ends with a pocket or recess exposing a portion of said conductor, of an electric coil of insulated wire wound upon said spool and having its inner end bared and in contact with the conductor in said pocket or recess.

3. A spool or bobbin for electrical coils, said spool being formed of insulating material and having a conductor buried in the material of said spool and thereby insulated, said conductor having an exposed bared end, a portionvof the material at the periphery of the spool intermediate its ends being rebeing removed to lay bare a portion of said conductor and form a pocket or recess of sufficient area to form a soldered connection.

In testimony whereof, I have hereunto set 15 my hand, in the presence of tWo subscribing Witnesses.

ROBERT C. DA COSTA.

Witnesses:

SAML. E. VILSON, HARVEY COOLEY. 

